The belief that arsenic levels in Washington County water fluctuate wildly over seasons or years
Many assume arsenic concentrations in groundwater fluctuate dramatically with seasons or from year to year. However, U.S. Geological Survey sampling data from March 2010 through April 2025, covering 16 wells ranging from 75 to 1000 feet deep in Washington County aquifers, show that arsenic was consistently detected in all 129 samples. The recorded range was from 0.12 to 35.6 micrograms per liter, with a median of 7.3 micrograms per liter over this 15-year span. While there is variation, the data do not indicate extreme seasonal swings but rather a relatively stable presence of arsenic within this range over time.
The misconception that aesthetic secondary standards are reliable health-based limits for arsenic
Aesthetic secondary standards often concern water constituents that affect taste, color, or staining and are not health-related limits. In the case of arsenic, federal thresholds exist that define health-based limits, but the Washington County data set includes no samples exceeding any federal arsenic threshold. This means arsenic levels found in the sampled wells do not violate safety standards. Aesthetic standards, which may influence perceptions about water quality, do not apply to arsenic removal decisions and should not be conflated with health risk assessments.
The notion that plumbing materials or the age of household pipes affect arsenic levels in tap water
Arsenic presence in household water primarily reflects the source groundwater rather than any influence from household plumbing materials or pipe age. While plumbing can impact water chemistry and contribute to corrosion or leaching of metals, arsenic does not originate from typical household plumbing components. Testing should focus on source water conditions rather than assuming plumbing alterations will change arsenic content.
What to record before seeking arsenic treatment advice
Before consulting about arsenic treatment options, document the following:
- Source of your water: well, municipal, or other.
- Depth and location of your well, if applicable.
- Recent laboratory test results specific to your water supply, particularly arsenic concentration.
- Any changes in water taste, appearance, or odor over time.
Such details are crucial because arsenic presence varies by specific water source and cannot be presumed from regional data alone.
Water quality symptoms commonly attributed to arsenic that do not indicate its presence
Unlike constituents causing noticeable stains or taste changes, arsenic is tasteless and odorless in water at naturally occurring concentrations. Symptoms such as discoloration, unusual odors, or sediment are more likely related to other factors. Arsenic impact is not detectable by sensory cues and requires laboratory analysis to confirm.
What not to conclude from Washington County arsenic data
Do not assume that because arsenic was detected in all sampled wells within the region, your household water has the same concentration or exceeds safety thresholds. Regional figures illustrate the presence and range of arsenic in local aquifers but do not define your water’s exact quality. Only specific testing of your own water supply can determine your arsenic levels. If treatment is needed, the C-Series Arsenic Filter ships ready to configure for residential use and has documented capability to reduce arsenic levels effectively.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2025-04-23. These figures describe groundwater sampled in this area. They are not a test of any individual private well - only a test of that well can establish its own water.
On record: U.S. Geological Survey sampling of Arsenic in the aquifer (Washington County): 129 results from 16 wells, median 7.3 ug/L, range 0.12-35.6 ug/L; none above any federal threshold